犁旋组合式油菜播种开沟起垄装置设计

Design of plow-rotary style ditching and ridging device for rapeseed seeding

针对中国南方稻田土壤黏重、高含水率土壤使传统油菜开沟起垄机构作业后沟壁易垮塌影响垄沟排水和后期油菜生长,研制了犁旋组合式油菜播种开沟起垄装置。设计了犁体式成沟起垄部件的入土角、翼板角度和翼板长度等结构参数,优化了旋转式切土部件的旋耕弯刀、沟壁切土直刀的安装方式及其结构参数。在室内土槽进行了多因素二次正交旋转组合试验,结果表明:影响沟面宽稳定度、垄高稳定度的主次顺序为沟壁切土直刀的回转半径、翼板长度、翼板角度;影响回土率的主次顺序为翼板长度、翼板角度、沟壁切土直刀的回转半径。装置最优的工作参数组合为沟壁切土直刀的回转半径为351 mm,翼板长度为78 cm,翼板角度为41°。对最优工作参数组合进行试验验证,各评价指标试验结果与软件分析值的相对偏差均不超过1%。该研究可为油菜垄作高产栽培提供技术参考。

The crop rotation of rice and rapeseed is the main planting pattern for winter rapeseed in South China. In a traditional broad-ridge shallow-furrow planting mode, the ditching machine plow or rotary disc is used to ditch the field. However, the plow cannot solve the problem of high rice stubble in field, while the rotary disc is easy to be entangled by grass and backwater mud in high humidity field, which often causes the traditional parts of ditching and ridging for rapeseed to be loose and collapse. Aimed to solve the problem of high stubble of rice after harvesting and reduce the influence of high-water content in sticky soil, in this paper, a plow-rotary style ditching and ridging device for rapeseed seeding is designed, which can meet the requirements of narrow ridge and deep ditch. Based on the maximum transported soil volume and the triangular wedge model, the structural parameters such as the embedded angle, the angle of the wing and the length of the wing are designed. The installing way of the rotary machetes and the straight tilling blade are innovated in the same roller. The turning radius and the length of each functional blade are optimized based on the biggest installation space, the uniformity coefficient of groove surface, the stability of ridge high and the soil return rate are taken as evaluating indicator. The turning radius of straight cutting blade, and the length and angle of wing are taken as experiment factors, and the multifactor quadratic orthogonal rotation combination test was carried out. The quadratic model is selected to establish the regression model which is related to the uniformity coefficient of groove surface, the stability of ridge high and the soil return rate. The F test and variance analysis are carried out for the coefficients of the regression model to establish quadratic multiple regression model related to the evaluation indices and influence factors. The results show that, the order of the factors influencing the uniformity coefficient of groove surface and the stability of ridge high from high to low is the turning radius of straight cutting blade, the length of wing and the angle of wing; the order of the factors influencing the soil return rate from high to low is the length of wing, the angle of wing and the rotary radius of straight cutting blade. The optimal combination of operating parameters is obtained after the application of the optimization function of the software: The turning radius of straight cutting blade is 351 mm, the length of wing is 78 cm and the angle of wing is 41°. And the evaluation indices are analyzed and the optimum values are selected: The uniformity coefficient of groove surface and the stability of ridge high reach the maximum values, and the soil return rate gets the minimum value. The optimal combination of operating parameters is verified, which meets the design requirements. All of the evaluation indices are basically the same as the software analysis, and the relative errors are less than 1%. The study results may provide technical support for high yield cultivation of rapeseed ridge planting.